Abstract
The formation of methylmercury compounds from inorganic mercury in vivo was investigated in rats and fish.
1. Chemical methylation of mercuric chloride mercurochrome with methylocbalamine, a vitamin B12 analog, was confirmed in vitro experiments.
2. In rats exposed to inorganic mercury, methylmercury formation was not accelerated by the injection of methylcobalamine.
3. A small quantity of methyl mercury compound was formed in rats administered inorganic mercury without methylcobalamine.
The methylmercury content was particularly increased in the kidneys.
4. In homogenates of whole fish, 203Hg-labeled methylmercury compound was found 10, 21 and 101 days after the injection of labeled mercuric chloride.
5. No difference in degree of methylation was noted among various spesies of fish: catfish, carp and trout.
Therefore the high level of methyl mercury in tuna and catfish in non-polluted water, as reported in the 2nd report, appeared to be unrelated to the high activity of biological methylation in vivo.
